In a heavy bottomed soup pot, cook bacon until fat begins to render.,Add diced vegetables and saute until wilted.,Add oregano, bay leaves, garlic and cayenne.,Stir in clams and their juices, continuing to saute for 2 more minutes.,Add the tomatoes and water, bring all to a boil.,Reduce heat and simmer for 1 hour.,Add potatoes and simmer for another 30 minutes.,______,Serve hot with freshly grated horseradish as a garnish.